A new map produced by the United States and California Geological Surveys stops short of predicting where landslides may occur, but does show which areas are prone to them.

On a new map produced by the United States and California
Geological Surveys, a stretch of orange and red extends on
the coastal range from Los Angeles to Oregon and patches of Orange
can also be seen in the Sierra and in Tehama County.

These are the areas where the slopes are steepest and the rock
strength is weakest. Tim McCrink with the CGS says this
is the first map they have produced that combines the two as they
try to better predict where slides will occur..

"We do plan to take this map into the next stage where we look
at the triggering mechanisms for landslides…both rainfall levels
and earthquake shaking levels."

McCrink says the Sierra presents an interesting dynamic as it
has plenty of granite…which is strong but also has plenty of
earthquake activity, rainfall, steep slopes and weaker rock mixed
in.